complete issue - IMA Fungus

the wild yeasts were beneficial to growth
under 12 sets of conditions tested. In yeasts,
it has consequently now been established
that prions are a naturally present
supplementary source of inheritable material
of adaptive value. The extent of prions in
filamentous fungi as a whole has yet to be
assessed, but they clearly have the potential
to contribute to adaptability and fitness.
volume 3 · no. 1
Halfmann R, Jarosz DF, Jones SK, Change A,
Lancaster AK, Lindquist S (2012) Prions
are a common mehcnisms for phenotypic
inheritance in wild yeasts. Nature 282:
363–368.
True HL, Lindquist SL (2000) A yeast prion
provides a mechanism for genetic variation
and phenotypic diversity. Nature 407:
477–478.
Different fungal and algal genotypes demonstrated
within one lichen specimen
Observations on the development of lichens
in the field reveal that multiple propagules
of a species developing on a surface often
116
P4T7e
104
P3T4c
108
P4T7
102
P3T4
113
P1T8
103
P5T3
106
P5T3c
123
P4T7d
A single specimen of Parmotrema tinctorum showing the different fungal
and algal genotypes determined with PCR of SSR markers. Codes prefixed
by P are of the fungal partner, and those by T are of the algal partner; five
fungal genotypes and one algal genotype were detected within this particular
98
specimen. P3T6 Adapted from Mansournia et al. (2012).
Yeast colonies, light and tramsmission electron
micrograph photos of Saccharomyces cerevisiae.
coalesce to form a single structure. This is
frequently observed where the propagules
are asexual soredia or isidia, which may
or may not have
come from the same
parent, and is welldocumented.
However,
whether all had to be
of a single genotype
for this to occur was
uncertain. The first
study to suggest that a
single lichen specimen
might not just have a
single fungal partner
experimentally was
the study of Larson
& Carey (1986) who
found that single
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P6
Tabcde
120
P6
Tabcde
124
P6
Tabcde
specimens of two
Umbilicaria species
showed variations
in physiological
parameters and
isoenzyme profiles.
With the advent
of DNA PCR
technology, and
especially the use of
microsatellite (SSR)
markers, it has become
possible to explore the
issue of the degree of
individuality of single
lichen specimens
with respect to both
the fungal and the
algal populations that
comprise them.
Parmotrema tinctorum is a rather
common tropical lichen that reproduces
mainly by asexual isidia. Mansornia et
al. (2012) studied populations growing
on Pinus thunbergii in Japan, and used
microsatellite markers to characterize the
partners at different levels: within single
specimens, on single trees, and within 10 x
10 cm quadrats. Of particular interest were
the results from single specimens in which
they studied numerous small pieces of tissue.
They found that a single specimen could be
formed from a single fungal partner with
or without changes in the algal partner,
or fusion of several independent partners.
In total 12 fungal genotypes and 37 algal
genotypes were recognized. An example in
which there were five fungal genotypes and
a single algal genotype is illustrated here.
Further, specimens from individual trees
or which were close together tended to
have similar genotypes, suggesting limited
dispersal in the site.
This study provides evidence to support
what has long been suspected, that one
cannot presume that what looks like a single
individual lichen specimen represents a
single fungal genotype.
Larson DW, Carey CK (1986) Phenotypic variation
within “individual” lichen thalli. American
Journal of Botany 73: 214–223.
Mansournia MR, Wu B, Matsushita N, Hogetsu T
(2012) Genotypic analysis of the foliose lichen
Parmotrema tinctorum using microsatellite
markers: association of mycobiont and
photobiont, and their reproductive modes.
Lichenologist 44: 419–440.
REsEARcH NEWs (31)